Lifting jack



March 21, 1933. A. HORVATH .902,448

LIFTING JACK Filed July 8, 1931 2 Sheets-Sheet 1 Inventor March 21, 1933- A. HORVATH LIFTING JACK Filed Jul y 8, 1951 2 Sheets-Sheet 2' Inventor Jzzizioyfirua i6 Patented Mar. 21, 1933 PATENT ence] ANTHONY HORVATH, or WALLINGFORD, CONNECTICUT marine JACK I Application filed my a, 193.1. 'SerialNo. 549,516. I

This invention having reference to what is known in the art as a lifting'jack, has for its primary object the provision OflIllPlOVECl means for raising and lowering the load sup- 5 porting part of the jack whereby to increase 7 following description, taken in connection with the accompanying drawings, the'jack is susceptible to almost any and all uses requiring a positive and eliicient load raising or lowering structure.

In the drawings: Figure 1 is a rear elevational view of th jack.

Figure 2 is a horizontal sectional view taken substantially on the line 2'2 of Figure 1. i I

Figure 3 is a side elevational View of the jack, the same being shown mounted on a support.

Figure 4 is a horizontal transverse sectional view taken substantially on the line 44 of Figure 3. V

Figure 5 is a transverse horizontal section taken on the line 55 of Figure 1.

Figure 6 is a fragmentary detail sectional elevational view illustrative of certain details of a detent embodying the features of the present invention.

Figure 7 is a perspective view of an end portion of the rack bar.

lVith reference more in detail to the drawings, it will be seen that 10 designates'gererally what may be lZGIIHGClEL rack bar, and which in the present instance is in the nature of a T-bar, the head flange 11 of which, at one edge is provided with a series of longitudinally spaced notches 12, which as best suited to this invention, are substantially semi-circular. i

ably secured thereto and extending transture, which also includes a-disk23 provided Shiftablelongitudinally of the rack bar, is-v a carriage designated generally by the reference character 13. i

As detailed in Figure ,5, carriage 13includes a body plate 14 paralleling and in sliding contact with the head flange 11 of bar-'10, and provided on one'face thereofwith a pair; of opposed guide cleats, 1'5, the op- I posed facesof which are notched or grooved as at'16 for ac commodatingthe longitudinal edge portion of the head flange 1 1. The cleats 1'5 are secured to the plates 14 by suitable fasteningelements-"=17; Body plate "1a of the carriage at its lower edge has suitversely thereof a "work 7 supporting-angle bar 18. (SeeFigur'es 1 to 3inclusive)."

Body plate ll-of'the-carriage at; one'edge thereof is provided with aslatera'l lug 19 to which is pivoted as at 20 a bell? crank '21.

Bell crank21at'one end thereof is provided with a boss, in which i's j ournalleda pin 22; Pin22 constitutes a part of a detent struc on one endofthe pin 22. Opposed rollers 24 are 'journalled on eccentric pins 25 suitably secured to the disk- 23,-and connected ibya bar 26. I

Rollers 2,4 are, engageable .withthe notches 12' and a study ofFigure'G will" show that the rollers 24:, are disposed inwardly of the periphery o-fdisk-23, and the ends of bar 26' so thaticasual displacement. of a. roller vfrom a. notch12 laterally with respect .to thehead g flange 11 ofthe -bar1'0,.an'd asfmaybecaused by: anxa'xial. shifting movement of pin, 22is guarded against. f' p i The free end of pin 22 is equipped with a suitable crank, handle 27,.and; froina study of Figure 3, it will be seen'that upon rotation of. the crankhandle 27," disk 23, and associated parts will rotateabout the axisof the pin'22 for alternately engaging; and dis engaging the rollers 24 "with the notches 12 to effect an ascentiordescent otthe-carriage 13. Bell crank lever-21 isnormally urged in one directionj'vto t-herebyz yieldably. retain the rollers 245511 engagement'withthe notches-12; 7

through the medium of: a retractile spring 199 28 connecting the free end of the bell crank with the work supporting angle bar 18.

In operation, and assuming that the device is to be used forsupportingan end of a scaffold platform. In the event of such, it

is apparent that at least two oppositely disposed jacks would be used each supporting an end of the scaffold platform, a portion of which is herein designated by the reference character P. 7

Now referring to Figure '3, the jack is first mounted, in a vertical position, ona suitable support S,-and to readily adapt a jack to any type of support, there is employed an angle bar 30 one flange of which may be bolted to the support as at 31, while to the second flange of the anglebar 30, is bolted the rib flange 11a of the T rack bar 10. (See Figure 1). V v r v -Now, with the parts in the position shown in Figure 3, that is with the carriage 13 in a lowered position, and platel8 of the carriage supporting one end of the platform P, let it be assumed that the platform P is to be raised a certain distance. Rotation ofthe handle 27 in, a clockwise direction, thus'rotating the disk 23'of the detent structure in a corresponding direction, results in the upper roller 24 remaining in engagement with its notch 12 thus causing disk 23, bar 26, and the lower roller 24 to rotate about the axis of the upper roller 24 whereupon said lower roller 24 will move out of its notch 12, to be subsequently received in that notch 12 of the rack bar directly above the notch occupied by the aforementioned upper roller, carriage'13 thus having travelled upwardly the distance between the two adj acent notches Continued repetition of the operation just described will efl'ect a step by step raising movement of the platform P. The lower the platform the operation is obviously the reverse. a i I It is believed that a thorough understanding of the construction, operation and utility of an invention of this character will be apparent to thoseskilled in this art from a a series of longitudinally spaced notches adjacent one edge thereof, a carriage embracing said bar 'and-shiftable longitudinally mounting said rotatable member on the carriage for movement toward and away from said bar, opposed eccentric pins on said rotatable member cooperable with the notches of said bar for efiecting shifting movement of the carriage, and means for rotating said rotatable member. c 2. In a jack, a bar provided with a series of relatively spaced'notches, a lifting device provided withv means engaging the bar to constrain the lifting device to shift longitudinally of the-bar, a lever pivotally mounted on the lifting device,'a member rotatably mounted on the lever, and having a pair of relatively spaced'pins to engagethe notches of the bar, and a handle for rotating the member. v

3. In a jack, a bar, a lifting device constrained to shift relative to the bar and provided with opposed guide cleats laterally engaging the bar, and means for shifting the lifting device comprising a-member rotatably' mounted on the lifting device, and a pair of rollers eccentricallymounted on the member and engageable with the bar, and means for rotating said; member.

-. In testimony whereof I affix my signature.

- ANTHONY HORVATH.

'thereof, a rotatable member, means for I i I 

